Lock stitch sewing machine with locking thread replenishing means



Dec. 24, 1963 s. J. KETTERER LOCK STITCH SEWING MACHINE WITH LOCKING THREAD REPLENISHING MEANS 7 Sheets-Sheet 1 Filed Dec. 12, 1960 5 EN 5 Na EN 82 383 5 8 N8 2 Q8 W 8M Na ma N2 8 we n n .3? 3 a m g 5 Q H M ON .h t a h v 4% 5r E 1 m2 RN m 2N N f wwn N I MN 2 Y. q 8 a 8 5 EN EN 8 N H n 4 3 l 1):. n m m I 3 m 3 u a is. mm 1} 9 mm M n .H l l mm M81; 1 1 L14. p m/ 1 z l s n E mm mv I 24 t n w m l l v S 3 8 .5

IN VEN T OR. STANLEY J. KETTERER fi/ITTORNEY WITNESS Dec. 24, 1963 5. J. KETTERER 3,115,110

LOCK STITCH SEWING MACHINE WITH LOCKING THREAD REPLENISHING MEANS Filed Dec. 12, 1960 7 Sheets-Sheet 2 r ll ' INVENTOR. STANLEY J. KETTERER WITNESS Dec. 24, 1963 S. J. KETTERER LOCK STITCH SEWING MACHINE WITH LOCKING THREAD REPLENISHING MEANS Filed Dec. 12, 1960 7 Sheets-Sheet 3 IN V'EN TOR. STANLEY J. Ks TTERER ATTORNEY Dec. 24, 1963 5. J. KETTERER 3,115,110

LOCK STITCH smwma MACHINE WITH Locxiuc THREAD REPLENISHING MEANS Filed Dec. 12. 1960 7 Sheets-Sheet 4 Dec. 24, 1963 s. JJKETTERER 3,115,110

LOCK smca SEWING MACHINE WITH LOCKING THREAD REPLENISHING MEANS Filed Dec. 12, 1960 7 Sheets-Sheet 5 E 2| 266 l9l 255 ZIO 1 I 1 r 200 1 19s I98 ZOI Fig. 7 2

INVENTOR. STANLEY J. KETTERER WITNESS.

TTORNE) Dec. 24, 1963 s. J. KETTERER 3,115,110

LOCK STITCH SEWING MACHINE WITH LOCKING THREAD REPLENISHING MEANS Filed Dec. 12. 1960 7 Sheets-Sheet 6 IN VENT OR. 7 STANLEY J. KE TTERER g u a T ORNE Y Dec. 24, 1963 5. J. KETTERER LOCK s'rI'rcH SEWING MACHINE WITH LOCKING THREAD REPLENISHING MEANS '7 Sheets-Sheet '7 Filed Dec. 12. 1960 Fig. l2.

IN VEN TOR. STANLEY J. KETTERER WITNESS.

ORNEY United States Patent M 3,115,110 LOCK STITCH SEWING MACHINE WITH LQCKENG TAD REPLENEHING MEANS Etanley J. Ketterer, Morris Plains, N..l., assignor to The Singer Qornpany, a corporation of New .lersey Filed Dec. 12, 196i), Ser. No. 75,387 31 Claims. (6!. 1Ii2--l81) This invention relates to sewing machines of the lock stitch type in which an upper or needle thread is manipulated by a loop taker completely about a supply of under or bobbin thread and the two threads thus concatenated are set into the work fabrics. More particular- 1y, this invention relates to novel and improved mechanism in a lock stitch sewing machine for automatically replenishing the supply of under or bobbin thread during the normal operation of the sewing machine.

It is an object of this invention to provide a mechanism for at will automatically replenishing the under or bobbin thread supply of a straight stitching non-cyclic lock stitch sewing machine Reference is made to the co-pending United States patent application of Ketterer and Herron Serial No. 73 6,748, filed May 21, 1958, now Patent No. 3,012,530, wherein is disclosed a bobbin thread replenishing mechanism illustrated in the preferred embodiment as applied to a cyclically operable sewing machine. Whereas certain of the principles of thread handling during bobbin replenishment disclosed in the above reference patent application have general utility and are applicable also to noncyclic sewing machines, the provision of this type of bobbin replenishing mechanism in a non-cyclic sewing ma chine gives rise to many problems not encountered where cyclic sewing machines are involved. It is to the recognition and solution of these problems which this invention relates with the object of providing a workable and commercially acceptable bobbin replenishing mechanism for a straight stitching non-cyclic lock stitch sewing machine.

In contrast with so-called straightaway sewing machines, cyclically operated sewing machines inherently include programming means, such as pattern cams or the like, which may be utilized to coordinate automatically the bobbin thread replenishing and the normal sewing operations. It is an object of this invention to provide operator influenced means for at will initiating the bobbin thread replenishing function during continued operation of the stitch forming instrumentalities of the sewing machine in a manner as is required for the formation of lock stitches.

Since in cyclically operated sewing machines the bobbin thread replenishing is controlled by the programming mechanism of the sewing machine, the conditions such as the position of all the parts etc., upon each initiation of bobbin thread replenishment may be relied upon and the bobbin thread replenishing mechanism may thus be designed, constructed, and adjusted for such invariable conditions. It is an object of this invention to provide a bobbin thread replenishing mechanism which will operate successfully and unfailingly over a wide range of different conditions, such as position of the parts, etc. upon each initiation of bobbin thread replenishment at the will of the sewing machine operator.

In cyclic sewing machines the amount of thread con sumed during successive sewing operations is substantially uniform with only minor variations stemming from such aspects as work thickness, bight, or stitch adjustment etc. In a conventional straightaway sewing machine, however, the thread consumption depends upon the Will of the machine operator who may wish to sew first a long hem and next secure a button in place with but a few stitches. It is an object of this invention to provide a 3,ll5,ll Patented Dec. 24, 1963 convenient means under control of the operator for selecting the amount of thread to be replenished in the bobbin during each operation of the bobbin thread replenishing means.

In this regard it is also an object of this invention to provide a means for replenishing accurately metered amounts of bobbin thread in far larger quanties than has been heretofore feasible.

It is an object of this invention to provide a sewing machine thread take-up mechanism with a throw-out device operable to render the take-up mechanism ineffective to influence the flow of thread to the stitch forming mechanism.

Since in a straightaway sewing machine far larger quantities of bobbin thread may be required for particular sewing operations than with conventional cyclic sewing machines, a problem arises in the adverse effect of the conventional needle thread take-up mechanism on the bobbin thread replenishing process. It is an object of this invention, therefore, to provide a novel combination of a thread take up throw-out mechanism and a means for operating the thread take up throwout mechanism during the bobbin thread replenishing operation.

Conventional straightaway sewing machines also differ from the usual cyclically operable variety in the use of a work feeding mechanism capable of advancing the Work continuously in one direction such as a drop feed rather than a shiftable work clamp. Whereas discontinuing of the work feed in a cyclic machine involves merely immobilizing the Work clamp, it is an object of this invention to provide a novel combination of a drop feed throw-out and means for operating the feed throw-out only during bobbin thread replenishing operations.

With the above and additional objects and advantages in View as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 is a vertical cross sectional view taken lengthwise through a sewing machine having this invention applied thereto,

FIG. 2 is a head end elevational view of the sewing machine of FIG. 1 with the bracket arm end cover plate removed,

FIG. 3 is a bottom plan view of the sewing machine of FIG. 1,

FIG. 4 represents a perspective view of the sewing machine of FIG. 1.

FIG. 5 represents an enlarged bottom plan view of the feed throw-out mechanism with portions illustrated in horizontal cross section taken substantially along line 5-5 of FIG. 2,

FIG. 6 is a vertical cross sectional view of the indexing mechanism taken substantially along line 66 of FIG. 3,

FIG. 7 is a vertical cross sectional view taken substantially along line 7-7 of FIG. 3,

FIG. 8 represents an enlarged top plan View of the loop taker with the loop taker supports and drive mechanism illustrated in horizontal cross section and including fragments of the members for actuating the bobbin thread replenishing control shaft,

FIG. 9 represents an enlarged face view of the loop taker,

FIG. 10 is a cross sectional View of the loop taker taken substantially along line Ill-1i of FIG. 9,

FIG. 11 represents an enlarged elevational View of a fragment of the sewing machine bracket arm in the vicinity of the needle thread take up mechanism, with a portion of the bracket arm illustrated in cross section taken substantially along line l111 of FIG. 2,

FIG. 12 represents an eievational view of the take up throw-out mechanism of FIG. 11 and,

FIG. 13 represents a top plan view of a fragment of the take up and take up throw-out mechanisms.

Referring to the drawings, this invention is embodied in a sewing machine having a frame including a bed 21 formed with a cloth plate 22, a hollow standard 23 rising from the bed and a bracket arm 2 carried by the standard and overhanging the bed. The bracket arm is open at the end opposite the standard, referred to in the art as the sewing head, and adapted to be closed by an end cover plate 25. The bracket arm is also open at the top and adapted to be closed by a top cover plate 26. To the bottom of the bed may be secured cushioning pads 27 or any of a variety of other known supporting means such as support pins, hinges etc., depending upon the surface or supporting table with which it is desired to use the sewing machine. The cloth plate of the bed beneath the bracket arm sewing head is fitted with a throat plate 2 8 apertured in the conventional manner to accommodate the needle and the feed dog. A cloth plate extension 29 may also be hinged to the bed.

Journaled in bushings 31-31 in the bracket arm is an arm shaft 32 to which is fast a drive gear 33 and a balance wheel 34. An electric motor 3:3 secured within the hollow standard and the bed is connected in a known manner to the drive gear 33 to drive the arm shaft. A receptacle 3-6 secured in the standard provides for the reception of a plug supplying electrical current to the motor, for a connection to a conventional operator influenced motor controlling rheostat or the like and for a supply of electrical current for illumination and for signaling devices to be described hereinbelow.

The armshaft 32 has secured thereto at the balance wheel 34 a counterbalanced crank 37 including a crank pin 38 embraced by a drive link 39 pivotally connected to a needle bar 40 endwise reciprocable in a bushing 4-1. in the bracket arm sewing head and having a needle 42 clamped thereto. An auxiliary crank pin 43 offset from the crank pin 33 is embraced by one arm 44 of a take up lever of which the other arm 45 extends exteriorly of the bracket arm and has a U-shaped extremity 46 formed in each limb with a thread eyelet 47, 47. The take-up lever 44-45 is pivoted to an anchor link 48 fulcrurned on a screw 49 secured in the bracket arm.

Carried for endwise movement in the bracket arm parallel to the needle bar is a presser bar 51 which is spring biased downwardly and fitted at the lower extremity with a presser foot 52. A collar 53 on the presser bar is disposed in the path of a cam 54 formed on a presser lifting lever 55 fulcrumed at 56 in the bracket arm providing a means for elevating the presser foot for removal or replacement of work fabrics thereunder.

Also secured on the bracket arm is a thread tensioning device 57 which may be of any conventional type and includes an axially shiftable tension releasing pin 58. A bell crank 59 biased by a spring 60 is fulcrumed in the bracket arm at 61 and is formed with an abutment 62 engaging the tension release pin 58 and with an offset 63 disposed in the path of a pin 64 projecting from the presser lifting cam 54 so that the thread tension will be released whenever the presser foot is raised. In normal sewing, the path of the sewing thread to the needle occurs from a supply spool (not shown) to the thread tensioning device 57 then to the eyelets 47-47 of the take up lever, and then to the needle eye. Release of the tension upon raising of the presser foot provides for free flow of the needle thread when work is withdrawn from the machine.

Cooperating with the needle in the formation of lock stitches is a loop taker, indicated generally at 70, which is carried in the bed beneath the throat plate on a hollow loop taker shaft 71 journaled in bushings 72-72 in the bed. The loop taker '70 is preferably of the type known in the art as a rotary hook in that it includes a needle loop seizing beak 73 which serves to engage and carry successive loops of needle thread about a supply of thread, referred to as bobbin thread, housed completely within the loop taker. The loop taker is preferably rotated two revolutions for each needle reciprocation and in timed relation with the needle by means of a shaft 74 journaled in the standard and driven by a set of bevel gears 75-75 of which one is secured to the arm shaft 32 and operatively connected to the hollow loop taker shaft by another set of bevel gears 7676.

Secured to the arm shaft 32 and preferably formed integral with the loop taker driving bevel gear 75 are a pair of feed actuating eccentrics '77 and 78. The feed lift eccentric 77 is embraced by the strap of a feed lift pitman 79 which extends downwardly through the hoilow standard and is pivotally connected at 80 to a rock arm 81 fast on a feed lift rock shaft 82 journaled in the bed. The feed advance eccentric '73 is embraced by a bifurcated head 33 formed on a feed advance pitman 34 which extends through the standard and is pivoted at 85 to a rock arm 86 formed on a feed advance rock frame 87 journaled in the bed. A slide block 83 pivotally secured by the threaded fastener 89 to the feed advance pitman is slidably constrained in a slotted guide block 90 fulcrumed on the pin 91 in the standard 23 and anguarly adjustable to control the magnitude of feed advance motion imparted to the feed advance rock shaft by means of an operator influenced stitch length adjusting handle 92 protruding through the front wall of the standard.

The work feeding mechanism, as illustrated in the drawings, is of the four motion drop feed type including a feed dog 95 which operates upwardly through the throat plate in opposition to the presser foot and is carried by a feed bar 96. The feed bar is pivoted on a pin 97 sustained between upstanding rock arms 98 formed on the feed advance u'ock frame thus to impart feed and return motions to the feed dog. The feed lift motion is imparted to the feed bar by means of a rock arm 99 fast on the feed lift rock shaft 82. An elongate stud 100 is secured in the feed lift rock arm 99 and passes through an aperture 101 in a lever 102 fulcrumed on the feed lift rock shaft 82. A link 103 is pivotally connected, as at 104, to the lever 102 and at 105 to a depending arm 106 of the feed bar. A plunger 107 slidable on the elongate stud is formed with a frustoconical head 108 and is biased by a spring 109 on the stud 100 into engagement with a cortical seat 110 formed in the aperture 101 in the lever 102 to lock the lever 102 to the feed lift rock arm 99 establishing an operative feed lift connection between the feed lift rock shaft 82 and the feed dog. Should the plunger 107 be retracted along the stud 100 in opposition to the spring 109, the lever 10 2 will be disconnected from the feed lift rock arm 99 and a torsion spring 111 acting between the rock arm 99 and the lever 1&2 will bias the lever 102 into a position in which the feed dog will be lowered out of operation beneath the throat plate.

Referring now particulanly to FIGS. 8, 9 and 10, the loop taker preferably includes a cup shaped body portion formed with a hub 121 secured by one or more set screws 122 to the loop taker shaft. The body portion 120 is formed internally with an annular raceway groove 123, however, a portion of the raceway groove is formed partly in the cup shaped body portion and partly in a removable gib 124 secured to the body portion by one or more screws 1 2-5. The body portion 120 is formed with a peripheral gap 126 providing also a gap or discontinuity in the annular raceway groove 123 into which gap extends the loop seizing beak 73 which is formed as part of or secured to the loop taker body portion. Journaled in the raceway groove 123 is the bearing rib 127 of a dished bobbin case 128 formed with a rotation restraining finger 129. As illustrated in FIG. 2, the bobbin case is constrained from rotation by means of a pair of spaced rotation restraining lugs 130130 which may include resilient spring members 13113*1 carried beneath the throat plate and arranged to embrace the rotation restraining finger 129 of the bobbin case. A portion of the bearing rib 127 of the bobbin case adjacent the rotation restraining finger is cut away defining, as best illustrated in FIG. 8, an ingoing pocket 132 or termination of the bearing rib, and an outgoing pocket 133 or termination of the bearing rib. To the exterior of the loop taker body portion 121 is secured as by screws 134 a sheet metal thread camming member 135 having an outer edge 136 extending from the loop taker body portion. The bobbin case is formed interiorly with a stud 136 on which is journaled a bobbin 13'] held thereon by a screw 13 8.

The use of the terms ingoing and outgoing pocket might best be explained with reference to the manner in which a needle thread loop is manipulated by the above described loop taker during conventional lock stitch formation. The loop taker rotates in the direction indicated by the arrows in FIGS. 8 and 9, and upon seizure by the beak 73 of a needle thread loop from the needle which enters an aperture 139 formed in the bobbin case, the gap 126 in the raceway groove 1 23 is open to the cut away portion of the bearing rib 127 between the ingoing and outgoing pockets 132, 133. As the loop taker rotates, the seized thread loop will be carried thereby against the ingoing pocket 132. The loop of needle thread seized by the beak 73 will then be trapped against the ingoing pocket 132 when the gap 126 in the hook body portion moves out of registry with the cut away portion of the bearing rib 12 7 between the ingoing and outgoing pockets .132 and 133. Upon continued rotation of the loop taker body portion, the beak 173 will carry the seized loop about the bobbin case, one limb of the loop passing across the space 140 between the bobbin case 128 and inside of the cup shaped hook body portion 120 and the other limb passing across the exposed face of the bobbin case and onto the rotation restraining finger 129. In drawing the limbs of the thread loop across both sides of the bobbin case, the beak 73 will shift the thread trapped between the ingoing and outgoing pockets from the ingoing to the outgoing pocket there to await movement of the gap 126 into registration with the cut away portion of the bearing rib 1 27 between the pockets at which time the thread loop will no longer be trapped and can be drawn up off the rotation restraining finger 129 by the action of the take up. In passing completely about the bobbin case 128, the needle thread loop will, of course, become concatenated with any thread carried on the bobbin and extending to the work and thus a true lock stitch, Federal type stitch 301, will be formed.

It will be appreciated that the above described sewing machine provides for the sewing of lockstitch seams completely under the control of the operator who may start and stop the sewing machine operation at will, adjust the stitch length and direction of feed at will, and at will lift the presser device for removal and replacement of work thereunder. It is necessary for stitch formation that the needle be properly supplied with a thread leading from the take up and the tension device and that the bobbin have wound thereon sufficient thread to produce the length of seam desired.

Whereas it is known in the art to provide for removal of the bobbin so that a fresh supply of thread may be wound thereon or a replacement bobbin of thread to be substituted; and it is also known in the art to render the stitching mechanism of the sewing machine inoperative and while inoperative to provide a means for winding thread on the bobbin in place within the loop taker, this invention has for an object the provision of means whereby the operator may at will cause the replenishment of a selected quantity of thread on the bobbin during continued regular operation of the stitch forming instrumentalities.

, fast on the rod 164.

The advantages of this invention over the known prior art arrangements are manifold, the tedious and time consuming replacement and winding of bobbins is obviated. The operator is not called upon to follow a complicated procedure of clutching and unclutohing the drive of the stitch forming instrumentalities, the working being stitched need not be removed or disturbed on the sewing machine.- In fact, the operator need only select the amount of bobbin thread desired, and that only if it differs from his previous selection of that quantity, and signal the bobbin replenishing process to begin. The process of bobbin replenishment, its termination after the selected quantity has been supplied, and the resumption of normal stitching operation then proceeds automatically with the machine of this invention. Moreover, the resulting seam is distinguished by an absence of thread ends which in conventional sewing machines must always be separately tied and severed if a neat seam is to be produced.

The mechanism will now be described whereby the loop taker is rendered effective to wind a thread seized from the needle on the bobbin rather than to concatenate that thread about the bobbin as it does during normal sewing operation. Extending upwardly through an escutcheon plate 151} on the cloth plate 22 is a lever 151 having a pair of fulcrum ears 152 embraced in a bearing bracket 153 beneath the cloth plate. The lower extremity of the lever 151 carries a transverse pin 154 which works in the space between the bifurcated arms 155, 156 of a rock arm 157 fast on a shaft 158 journaled transversely in the bed. A wire link 159 engaging an eyelet in one of the bifurcated arms is secured to a lever 160 fulcrumed at 161 to the bed and having a bifurcated finger 162 which, as illustrated in FIG. 8, engages on opposite sides of a thrust washer 163 carried on a rod 164 slidable axially in the hollow hook shaft 71. A coil spring 165 is arranged between the washer 163 and a collar 1166 The rod 164 extends into the cup shaped loop taker body portion 12b and, as best illustrated in FIG. 10, a disk 167 is secured to the rod within the loop taker body portion. The disk 167 is formed with a radial arm 168 disposed in an opening 169 in the loop taker body portion adjacent the loop taker beak 73 so as to lock the disk 167 and the rod 164 for rotation with the loop taker. Moreover, the disk 167 is dimensioned for accommodation axially within the dished bobbin case 128 and has a face shape complemental to that of the bobbin 137 journaled within the bobbin case. An aperture 170 formed in the disk 167 accommodates a pin 1711 carried by a leaf spring 172 secured to the disk 167. The pin 171 is adapted drivingly to enter one of a plurality of circular segmental slots 173 formed in the bobbin when the rod 164 is shifted axially toward the loop taker.

When the lever 151 is turned by the machine operator toward the left, as viewed in FIG. 4, the lever 160 acting through the spring 165 shifts the rod 164 toward the loop taker, thus shifting the disk 167 to a position within the bobbin case, the pin 170 into one of the slots 173 in the bobbin, and the arm 168 of the disk against the side of the hook beak; Any loop of needle thread engaged by the beak 73 will be clamped thereon by the arm 168 and the clamped loop will be carried about the loop taker by the beak. The loop of thread on the beak will not, however, be cast about the bobbin case as in normal sewing because the disk 167 will have closed the space 1413 which usually exists behind the bobbin case. The space 141} being closed, that limb of the gripped thread loop which usually passes across and behind the bobbin case will be supported on the disk 1167 and thus maintained in the ingoing pocket 132 and urged outwardly by the thread oamrning member 135 of the loop taker.

The bobbin case 125 is formed with a slot 175 leading outwardly from the ingoing pocket 13'2 toward the exposed face of the bobbin case. The slot 175 is joined is disposed between the paths of the limbs of the U-shaped free extremity 46 of the take-up lever 45, and the thread engaging hook 239 when the slide bar 223 is raised, is disposed in the path of the thread extending between the eyelets 47-47 of the take-up 45. In dot and dashed lines in FIG. 12 is indicated the path of the thread extending between the eyelets 474'7 during one cycle of take-up operation. It will be noted that at the top of the take-up stroke the take-up eyeless 4-747 move inwardly toward the bracket arm and that the hook 239 of the auxiliary take-up 237 is disposed, when in operative position with the slide bar 228 raised, to engage the thread between the eyelets 4747'. So long as the bobbin replenishing mechanism remains in operation, therefore, the hook 239 of the auxiliary take-up will maintain the bight of thread usually controlled by the take up 45 in substantially the maximum state of expansion. The eyelets 47- 3 7 will during this interval rove or slide along the limbs of the thread bight maintained by the auxiliary take-up without substantially influencing the flow of thread to the needle. Immediately upon the lowering of the slide bar 228 occasioned by a shift to inoperative position of the bobbin replenishing means, the auxiliary take-up will be shifted to the dotted line position illustrated in FIG. 12 and will spill off the thread loop thereon and thus will immediately relinquish control of the thread to the take-up lever 45.

The mechanism will now be described whereby the amount of thread that is replenished in the bobbin may be selectively controlled by the sewing machine operator. Referring to FIG. 3, the arm 1% of the bell crank 34-195 carries a throw-out pin 25% which in the position of the bell crank i194, 1195 when the lever 151 is thrown to the right as viewed in PEG. 4 and while conventional sewing operations continue, makes contact with and shifts away from the ratchet wheel 1% a pair of pawls 251 and 252. The pawl 25-1 is a retrograde motion preventing pawl and is fulcrumed on a stud 253 car ried by the sewing machine bed and biased toward the ratchet wheel 1% by a coil spring 2%- anchored on a pin 255 depending from the shallow recess 1% of the cloth plate, as illustrated in FIG. 6. The pawl 252 is a ratchet wheel driving pawl and is pivoted, as at 256, on a lever 25) fulcrumed on the stud 253 and biased toward the ratchet wheel 19% by a spring 258 anchored on the pin 255. The lever 257 is pivotally connected to a drive link 259 formed with a spherical seat 260 which embraces a block 261 of spherical peripheral contour aperture slidably to accommodate a pin 262 secured for oscillation With the feed lift rock shaft 82.

The pawl 252 will thus be driven constantly during operation of the sewing machine but the pawls will be held out of operative engagement by the pin 25% while normal sewing operations occur and will be released into driving relation with the ratchet wheel 1% during bobbin replenishing operations.

Secured to the ratchet wheel as by a screw 2&5, illustrated in FIG. 6, is a torsion spring 266 anchored on the pin 255 so as to bias the ratchet wheel in a clockwise direction, as viewed in FIG. 3. A stop block 26 7 preferably provided with a cushioning pad 268 is carried by the ratchet wheel and serves in abutting the collar 197 to limit the motion of the ratchet wheel in response to the torsion spring 266.

The ratchet wheel also carries a cam block 270 which operates against a spherically headed follower pin 271 carried at one end of a follower lever 27?; formed with a free extremity 273 disposed vertically beneath the bore 192 in the bushing 191 and beneath the free extremity 294- of the latch lever 2%. When the ratchet wheel has been indexed by the pawl 252 sulhciently to cause engagement of the cam block 270 with the finger 271, the latch lever 202 will thus be tripped and the bobbin replenishing mechanism released for return to inoperative position in response to the spring 109 in the feed throw out mechanism.

The follower lever 272 is fulcrumed on a pin 274 carried in the downturned portion 27 S of an arm 276 secured to a shaft 277 journaled in the bore 192 of the bearing boss 191. Fixed on the shaft and disposed in the shallow recess 19%] in the cloth plate is a flat disk 278 the top surface of which is substantially flush with the top of the cloth plate so as not to impede the flow of Work fabrics thereover. A recessed finger grip 279 is formed in the disk to facilitate angular adjustment thereof and indicia 280 may be formed about the periphery to cooperate with a mark 281 formed on the cloth plate to indicate the position of adjustment. The indicia may be in abstract numbers, it may indicate the length of thread to be replenished in the bobbin, or it may indicate the length of seam possible under average conditions of stitch length, tension settings, and work fabric for the various possible positions of adjustment. An annular toothed ring 282 is fixed beneath the disk 278, as by screws 283, and cooperates with a locking finger 2:84 carried by a plunger 28 5 journaled vertically in the cloth plate and spring loaded by a spring 286. The plunger 285 must thus be depressed to release the disk 278 for an angular adjustment and when the plunger 285 is released the locking finger 284 then secures the disk in selected position of adjustment.

Fulcrurned on the latch lever fulcrum pin 203- and disposed beneath the latch lever 2% is a lever 2% having one free extremity 291 extending beneath the vertical axis of the shaft bore 192 and the other extremity 292 biased upwardly against the underside of the latch lever 20?; by the spring loaded arm 2% of a normally-open held-closed electrical switch 2% which is operated to close the switch by depression of the spring loaded arm 2%. An operat ing lever 295 for the switch is disposed beneath the fol lower lever 272 and fulcrumed on the fulcrum pin 274. The operating lever 295 is formed with a free extremity 296 disposed beneath the vertical axis of the shaft bore 192 and beneath the free extremity 291 of the lever 290 while at the opposite extremity the operating lever 295 carries a spherically headed follower pin 297 which is off set on that side of the cam follower pin 271 toward which the cam block 270 approaches upon indexing of the ratchet wheel. The switch 2% is connected electrically (wiring not shown) from the receptical 36 to a signal lamp 293 preferably carried in the bracket arm 24 although it will be apparent that a bell, buzzer or the like might also serve to indicate to the operator that bobbin winding is nearing conclusion. The switch 294 may also be connected into the electrical circuit supplying power to the motor 35 and serve to cut off power to the motor as the bobbin winding process nears conclusion.

When the bobbin replenishing means is thrown into operation, the movement of the latch lever 262 into latching engagement with the bell crank lever 194, 195 will release the switch arm 293 allowing the spring loaded switch arm to raise the extremity 292 of the lever 290 and the signal lamp 298 will be turned on. The signal lamp will remain on until the cam block 270 depresses the follower pin 297 shortly before the cam block 270 depresses the follower pin 271 to stop the bobbin winding process. When the signal lamp is turned off the machine operator will thus be forewarned that the sewing process is about to begin. The operator has an opportunity, therefore, to slow the speed of the motor if she wishes to initiate the sewing process slowly for more precise control of the seam formation or the like.

In the operation of the sewing machine of this invention, it is necessary that a free end of needle thread exists at the start of the bobbin replenishing process, the free end of thread must extend from the needle long enough to prevent the take-up from unthreading the needle before the needle thread loop is clamped against the loop taker beak by the thread clamping arm 16 8, and short enough so that the free end of thread extending from the needle will be drawn completely beneath the Work by the loop taker beak. Since the operator influenced lever 151 may be shifted at will by the operator to initiate the bobbin replenishing process, and therefore, this may occur with the needle and take-up disposed in any one of a range of positions, the length of the free end of thread extending from the needle which will be sumcient to satisfy both of these requirements will vary. A machine operator may standarize the amount of free end of thread required to extend from the needle by taking the precaution of operating the lever 151 and initiating bobbin replenishment only when the take-up occupies a predetermined position, as for instance, at the top of the take-up stroke. Similarly an operator will quickly learn by experience to compensate for the various take-up positions at the start of bobbin winding and to allow a proportionately greater length of free end of thread when bobbin winding is initiated before the takeup reaches the top of its stroke, and a proportionately smaller length of free end of thread when the process 15 initiated after the take-up has passed the top of its stroke.

The sewing machine of this invention, however, includes means for providing the proper free end of needle thread regardless of the point in the needle and take-up cycle at which the bobbin winding process is initiated. To this end, a conventional thread nipper and cutter, indicated generally at 3%, is secured to a bushing 331 in the bracket arm 11 in which the presser bar 51 is journaled. The nipper and cutter 399 preferably includes a body portion 302 secured to the bushing and a spring arm 3&3 biased against the body portion to nip .a thread introduced therebetween. The upper edge of the spring arm is formed with a sharpened cutting edge Eli iover which the nipped thread may be drawn and severed. The thread nipping pressure exerted by the spring arm 3G3 is preferably suliicient to retain a needle thread nipped therein against the action of the take-up member 45, and since the thread tensioning device 57 is released simultaneously with initiation of bobbin replenishing, the take-up will draw thread from the spool rather than from the needle.

The spring arm 3%, however, is sufficiently resilient as to release the nipped thread to the action of the loop taker beak when a needle thread loop is clamped thereon by the thread clamping arm 163. Furthermore, the thread nipper 380 is disposed relatively to the bracket arm to provide a length of free end of thread extending to the loop taker beak which will with certainty be drawn by the loop taker beneath the work.

The bobbin replenishing mechanism of this invention may be operated at the will of the sewing machine operator and with or without work fabrics beneath the presser foot. With work in place, the thread is replenished through the work and the succeeding seam will be distinguished by an absence of starting thread ends. When the thread is replenished without work in place, a seam without starting thread ends may be made only from the edge of a work fabric.

To initiate bobbin replenishment the operator need only actuate the lever 1551, taking care to nip the free end of needle thread in the nipper 3th? or to provide the appropriate length of free end of needle thread, and upon actuation of the sewing machine drive motor 35, the bobbin will automatically be wound with thread following which the machine will automatically be operated to form stitches using the replenished bobbin thread supply. Adjustment of the setting of the disk 27% prior to initiation of bobbin replenishment is necessary only when the operator wishes to replenish an amount of thread dilferent from that of the preceding replenishing operation.

Having set forth the nature of this invention what is claimed herein is:

1. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement in timed relation as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, a first operator influenced means for controlling the operation of said sewing machine actuating means, and a second operator influenced control means operatively connected to said locking thread replenishing means for at will rendering said thread replenishing means effective.

2. in a lock stitch sewing machine having a thread carrying needle, a loop taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement in timed relation as is required for the formation of lock stitches, locking thread replenishing means effective to replenish a supply of thread into said locking thread accommodating means of said looptaker during said operation of said needle and loop-taker by said actuatin means, operator influenced means for at will rendering said locking thread replenishing means effective, and means for regulating the amount of thread rcplenished into said locking thread accommodating means by the o eration of said locking thread replenishing means, it iuding means operated by said actuating means timed relation with said cooperating stitch forming move-m ats of said needle and loop taker for automatically rendering said locking thread replenishing means ineffective.

3. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting needle and loop-taker for re etitive cooperating movements in timed relation as are required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, means for at will rendering said locking thread replenishing means effective, latch means for maintaining said thread replenishing means in effective position, latch release means associated with said latch means, and means driven by said actuating means and responsive to a predetermined number of repetitive cooperating movements of said needle and loop-taker as are required for the formation of lock stitches for operating said latch rclease means.

4. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting needle and loop-taker for repetitive cooperating movements are are required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to introduce a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, means for at will rendering said locking thread replenishing means effective, latch means for maintaining said thread replenishing means in effective position, latch release means associated with said latch means, means driven by said actuating means and responsive to a predetermined number of repetitive cooperating movements of said needle and loop-taker as are required for the formation of lock stitches for operating said latch release means, and operator influenced control means for selecting said predetermined number of said repetitive cooperating movements of said needle and loop-taker required for operating said latch release means.

5. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connected to impart repetitive cycles of interrelated motions to said needle and loop-taker as are required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to introduce a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, operator influenced means for at will rendering said locking thread replenishing means effective, counting means carried by said sewing machine, pulsing means for indexing said counting means operated by said actuating means during each cycle of said interrelated motions of said needle, means operated by said operator influenced means for rendering said pulsing means effective to index said counting means when said locking thread replenishing means is effective, and means associated with said counting means and responsive to a predetermined indexing thereof by said pulsing means for rendering said locking thread replenishing means and said pulsing means ineffective.

6. In a sewing machine having a thread carrying needle, a loop-taker having a thread carrying bobbin journaled therein and said loop-taker disposed for manipulation of successive loops of needle thread about said bobbin as is required in the formation of lock stitches, and means connecting said needle and loop-taker for cooperating movements in timed relation as are required for the formation of lock stitches, bobbin winding means for directing a loop of needle thread carried by said loop-taker onto rather than about said bobbin to initiate Winding of needle thread on said bobbin, an operator influenced member carried on said sewing machine effective at the will of a sewing machine operator to render said bobbin winding means effective, and means operated in timed relation with said needle and loop-taker for rendering said bobbin winding means ineffective and automatically rendering said loop-taker effective to manipulate successive loops of needle thread about the bobbin in the formation of lock stitches.

7. In a sewing machine having a thread carrying needle, a loop-taker having a bobbin associated therewith, means operatively connecting said needle and looptaker for movement in timed relation, and means associated with said loop-taker for concatenating loops of thread carried by said needle about said bobbin in the formation of lock stitches, means associated with said loop-taker for winding a thread on said bobbin in place relatively to said loop-taker, shiftable control means carried by said sewing machine and having a bobbin winding position and a sewing position, means operatively connected to said control means and effective in said bobbin winding position thereof for rendering said loop taker ineffective to concatenate loops of thread about said bobbin in the formation of lock stitches, means operatively connected to said control means and effective in said sewing position thereof for rendering said loop-taker effective to concatenate loops of thread carried by said needle about said bobbin in the formation of lock stitches, an operator influenced member associated with said sewing machine for at will moving said control means into said bobbin winding position, and means associated with said sewing machine and operated thereby for automatically moving said control means into said sewing position.

8. In a sewing machine having an endwise reciprocatory thread carrying needle, a loop-taker having means therein to acocmmodate a locking thread, actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, a work feeding mechanism, means operated by said actuating means for operating said work feeding mechanism in timed relation with said lock stitch forming movement of said needle and loop-taker, a feed throw-out means associated with said work feeding means, and a needle thread controlling mechanism including a needle thread tensioning device, a needle thread tension releasing means associated with said tensioning device,

a needle thread take-up, and means operated by said actuating means for operating said needle thread take-up in timed relation with said lock stitch forming movement of said needle and loop-taker, locking thread replenishing means for introducing a supply of needle thread into said locking thread accommodating means in said looptaker during operation of said needle and loop-taker actuating means, an operator influenced member shiftably supported on said sewing machine for movement between two extreme positions, means biasing said operator influenced member toward one extreme position, latch means for constraining said operator influenced member in the opposite extreme position, means operatively connected to said operator influenced member and effective in the latched extreme position of said operator influenced member to render effective said locking thread replenishing means, said thread tension releasing means, and said feed throw-out means, and means for releasing said latch means.

9. In a sewing machine having an endwise reciprocatory thread carrying needle, a loop-taker having means therein to accommodate a locking thread, actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, a work feeding mechanism, means operated by said actuating means for operating said work feeding mechanism in timed relation with said lock stitch forming movement of said needle and loop-taker, a feed throw-out means associated with said work feeding means, and a needle thread controlling mechanism including a needle thread tensioning device, a needle thread tension released means associated with said tensioning device, a needle thread take-up, and means operated by said actuating means for operating said needle thread take-up in timed relation with said lock stitch forming movement of said needle and loop-taker, locking thread replenishing means for depositing a supply of needle thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, an operator influenced member shiftably supported on said sewing machine for movement between two extreme positions, means biasing said operator influenced member toward one extreme position, latch means for constraining said operator influenced member in the opposite extreme position, means operatively connected to said operator influenced member and effective in the latched extreme position of said operator influenced member to render effective said locking thread replenishing means, said feed throw-out means, and said needle thread tension releasing means, and means operated by said actuating means during operation of said needle and loop-taker for releasing said latch means.

10. In a sewing machine having an endwise reciprocatory thread carrying needle, a loop-taker having means therein to accommodate a locking thread, actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, a work feeding mechanism, means operated by said actuating means for operating said work feeding mechanism in timed relation with said lock stitch forming movement of said needle and loop-taker, a feed throw-out means associated with said work feeding means, and a needle thread controlling mechanism including a needle thread tensioning device, a needle thread tension releasing means associated with said tensioning device, a needle thread take-up, and means operated by said actuating means for operating said needle thread take-up in timed relation with said lock stitch forming movement of said needle and loop-taker, locking thread replenishing means for introducing a supply of needle thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker actuating means, an operator influenced member shiftably supported on said sewing machine for movement between two extreme positions, means biasing said operator influenced member toward one extreme position, latch means for constraining said operator influenced member in the opposite extreme position, means operatively connected to said operator influenced member and effective in the latched extreme position of said operator influenced member to render effective said locking thread replenishing means, said feed throw-out means, and said needle thread tension releasing means, a control member shiftably supported on said sewing machine, drive means operated by said actuating means for shifting said control member, means operatively connected to said operator influenced member and effective in the latched extreme position of said operator influenced member for rendering effective said drive means for said control member, and means associated with said control member for releasing said latch means.

11. In a sewing machine having an endwise reciprocatory thread carrying needle, a loop-taker having means therein to accommodate a locking thread, actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, a work feeding mechanism, means operated by said actuating means for operating said work feeding mechanism in timed relation with said lock stitch forming movement of said needle and loop-taker, a feed throw-out means associated with said work feeding means, and a needle thread controlling mechanism including a needle thread tensioning device, a needle thread tension releasing means associated with said tensioning device, a needle thread take-up, and means operated by said actuating means for operating said needle thread take-up in timed relation with said lock stitch forming movement of said needle and loop-taker, locking thread replenishing means for depositing a supply of needle thread into said locking thread accommodating means in said looptaker during said operation of said needle and loop-taker actuating means, an operator influenced member shiftably supported on said sewing machine for movement between two extreme positions, means biasing said operator influenced member toward one extreme position, latch means for constraining said operator influenced member in the opposite extreme position, means operatively connected to said operator influenced member and effective in the latched extreme position of said operator influenced member to render effective said locking thread replenishing means and said feed throw-out means and said needle thread tension releasing means, a control member shiftably supported on said sewing machine, drive means perated by said actuating means for shifting said control member, means operatively connected to said operator influenced member and effective in the latched extreme position of said operator influenced member for rendering effective said drive means for said control member, a cam element carried on said control member and having a path of motion upon shifting of said control member by said drive means, latch release means operatively associated with the latch means for constraining said operator influenced member and disposed in the path of motion of said cam means, and operator influenced means for at will shifting the position of said latch release means along the path of motion of said cam means.

12. In a lock stitch sewing machine having a reciprocatory thread carrying needle, a needle thread take-up mechanism for engaging and periodically expanding a loop of the thread carried by said needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, locking thread supply replenishing means driven by said actuating mechanism during said stitch forming movement of said needle and loop-taker and effective to replenish with thread from said thread carrying needle the supply of thread in said locking thread accommodating means in said loop-taker, take-up throw-out means effective including a means for constraining the loop of thread expanded by said takeup mechanism in a substantially fixed state of expansion and means for rendering said loop-taker supply replenishing means and said take-up throw-out means simultaneously effective and simultaneously ineffective.

3. In a lock stitch sewing machine having a thread carrying needle, a needle thread take-up mechanism, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, locking thread supply replenishing means for directing a supply of thread from said thread carrying needle into said locking thread accommodating means in said looptaker during said operation of said needle and loop-taker by said actuating means, take-up throw-out mechanism effective to suspend the effect of said take-up mechanism on the thread directed to said thread carrying needle, operator influenced means for at will rendering said locking thread replenishing means and said take-up throw-out mechanism simultaneously effective, and means operated automatically in timed relation with said actuating means for said needle and loop-taker for rendering said locking thread supply replenishing means and said take-up throwout mechanism simultaneously ineffective.

14. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, a work feeding mechanism including a feed member adapted to engage and advance a work fabric relatively to said needle, and actuating means operatively connecting said needle looptaker and work feeding mechanism for cooperating move ment as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish a supply of thread into said locking thread accommodating means in said ptaker during said operation of said needle and loop-taker by said actuating means, a feed throw-out means effective to disengage said feed member from said work fabric for rendering said work feeding mechanism ineffective to feed work relatively to said needle, and means for rendering said locking thread replenishing means and said feed throw-out means simultaneously effective and simultaneously ineffective.

15. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, a work feeding mechanism including a feed member adapted to engage and advance a work fabric relatively to said needle, and actuating means operatively connecting said needle, said loop-taker and work feeding mechanism for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish a supply of thread into said locking thread accommodating means in said loop-taker during said operating of said needle and looptaker by said actuating means, a feed throw-out means effective to disengage said feed member from said work fabric for rendering said work feeding mechanism ineffective to feed work relatively to said needle, 0 erator influence means for at will rendering said locking thread replenishing means and said feed throw-out means simultaneously effective, and means operated automatically in timed relation with said actuating means for said needle and loop-taker for rendering said locking thread replenishing means and said feed throw-out means simultaneously ineffective.

16. In a lock stitch sewing machine having a reciprocatory thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, a four motion drop feed mechanism effective to feed work continuously in one direction relatively to said needle and including a feed dog, feed advance and return mechanism, means operatively connecting said feed advance and return mechanism to said feed dog, feed lift mechanism and means operatively connecting said feed lift mechanism to said feed dog, and actuating means operatively connecting said needle, loop-taker, feed advance and return mechanism, and feed lift mechanism for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, a feed throw-out means including means for disabling the operative connections between the feed lift mechanism and said feed dog, and means for rendering said locking thread replenishing means and said feed throw-out means simultaneously effective and simultaneously ineffective.

17. In a lock stitch sewing machine having a reciprocatory thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, a four motion drop feed mechanism effective to feed work continuously in one direction relatively to said needle and including a feed dog, feed advance and return mechanism, means operatively connecting said feed advance and return mechanism to said feed dog, feed lift mechanism and means operatively connecting said feed lift mechanism to said feed dog, and actuating means operatively connecting said needle, loop-taker, feed advance and return mech anism, and feed lift mechanism for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, a feed throw-out means including means for disabling the operative connections between said feed lift mechanism and said feed dog, operator influenced means for at will rendering said locking thread replenishing means and said feed throwout means simultaneously effective, and means operated automatically in timed relation with said actuating means for said needle and loop-taker for rendering said locking thread replenishing means and said feed throw-out means simultaneously ineffective.

18. In a lock stitch sewing machine having a thread carrying needle, a needle thread take-up mechanism for engaging and periodically expanding a loop of the thread carried by said needle, a loop-taker having means therein to accommodate a supply of locking thread, a work feeding mechanism capable of feeding work continuously in one direction relatively to said needle, and actuating means operatively connecting said needle, loop-taker, take-up, and work feeding mechanism for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish with thread from said thread carrying needle the supply of thread in said locking thread accommodating means in said loop-taker, takeup throw-out means including a means for constraining the loop of thread expanded by said take-up mechanism in a substantially fixed state of expansion, feed throw-out means for rendering said work feeding mechanism inefective to feed work relatively to said needle, and means for rendering said locking thread replenishing means, said take-up throw-out means and said feed throw-out means simultaneously effective and simultaneously ineffective.

19. In a lock stitch sewing machine having a thread carrying needle, a needle thread take-up mechanism for engaging and periodically expanding a loop of thread carried by said needle, a loop-taker having means therein to accommodate a supply of locking thread, a Work feeding mechanism capable of feeding work continuously in one direction relatively to said needle, and actuating means operatively connecting said needle, loop-taker, takeup and work feeding mechanism for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to replenish with thread from said thread carrying needle the supply of thread in said locking thread accommodating means in said loop-taker, take-up throw-out means including a means for constraining the loop of thread expanded by said take-up mechanism in a substantially fixed state of expansion, feed throw-out means for rendering said work feeding mechanism ineffective to feed work relatively to said needle, operator influenced means for at will rendering said locking thread replenishing means, said take-up throw-out means, and said feed throw-out means simultaneously effective, and means operated automatically in timed relation with said actuating means for said needle and loop-taker for rendering said locking thread replenishing means, said take-up throw-out means, and said feed throw-out means simultaneously ineffective.

20. In a sewing machine having a frame, a thread carrying eye pointed needle carried in the frame, a looptaker journaled for turning movement in the frame having a needle loop seizing beak and a thread carrying bobbin associated therewith, and actuating means for operating said needle and loop-taker in timed relation causing said loop seizing beak to seize and carry loops of needle thread about said bobbin as is required in the formation of lock stitches, bobbin replenishing means comprising a thread clamping member rotatable with said loop-taker, means shiftably supporting said thread clamping member for movement into and out of thread clamping relation against said loop seizing beak, means shiftable with said thread clamping member and disposed when said thread clamping member is in thread clamping relation against said loop seizing beak to direct one limb of a needle thread loop gripped on said beak into said bobbin, an operator influenced member shiftably supported relatively to said sewing machine for movement into a bobbin winding position and a sewing position, means including spring means operatively connecting said operator influenced member to said thread clamping member to shift said thread clamping member into thread clamping relation with the loop seizing beak in the bobbin winding position of said operator influenced member, latch means for maintaining said operator influenced member in bobbin winding position, means operated in timed relation with said needle and loop-taker for releasing said latch means, and means operated automatically during each revolution of said loop-taker for momentarily shifting said thread clamping member in opposition to said spring means and out of thread clamping relation with said loop-taker beak during needle thread loop seizure by the loop seizing beak.

21. In a sewing machine having a frame, a thread carrying eye pointed needle carried on the frame, a looptaker journaled for turning movement in the frame having a needle loop seizing beak and a thread carrying bobbin associated therewith, and actuating means for op erating said needle and loop-taker in timed relation causing said loop seizing beak to seize and carry loops of needle thread about said bobbin as is required in the formation of lock stitches, bobbin replenishing means comprising a thread clamping member rotatable with said loop-taker, means shiftably supporting said thread clamping member for movement into and out of thread clamping relation against said loop seizing beak, means shiftably with said thread clamping member and disposed when said thread clamping member is in thread clamping relation against said loop seizing beak to direct one limb of a needle thread loop gripped on said beak into said bobbin, operator influenced means for at will shifting said thread gripping member into thread clamping relation, cam means carried for rotation with said thread clamping member, a cooperating cam follower supported relatively to said sewing machine frame and positioned momentarily to retract said thread clamping member out of thread clamping relation against said loop seizing beak in the loop seizing position of said beak during each revolution of said loop-taker.

22. In a sewing machine having a frame, a thread carrying eye pointed needle carried in the frame, a looptaker having a needle loop seizing beak and a thread carrying bobbin associated therewith, a hollow looptaker shaft fast with respect to said loop-taker and journaled in said frame, actuating means for operating said needle and loop-taker in timed relation causing the loop seizing beak to seize and carry loops of needle thread about said bobbin as is required in the formation of lock stitches, bobbin replenishing means comprising a rod slidable axially in said hollow loop-taker shaft, a thread clamping member rotatable with said loop-taker adjacent to said loop seizing beak and fast on said rod, means for shifting said rod axially to move said thread clamping member into thread clamping relation against said loop seizing beak including a collar fast on said rod, a coil spring abutting said collar on said rod, a lever fulcrumed on said sewing machine frame and abutting said coil spring, operator influenced means for at will shifting said lever into an operative position against said coil spring urging said thread clamping member into thread clamping relation, and latch means for maintaining said lever in said operative position, means shiftable with said thread clamping member and disposed when said thread clamping member is in thread clamping relation against said loop-taker beak to direct one limb of the needle thread loop gripped on said beak into said bobbin, a cam disk fast on said rod, a cam lobe formed on one face of said cam disk, a cam follower, means shiftably supporting said cam follower relatively to said sewing machine frame for oscillatory movement in a plane substantially perpendicular to said rod for engagement with said earn lobe during needle thread seizure by said loop seizing beak to shift said thread clamping member in opposition to said coil spring and out of thread clamping relation with said loop-taker beak, and means operated in timed relation with said needle and loop-taker for releasing said latch means to terminate winding of the bobbin.

23. In a lock stitch sewing machine having a work support, a thread carrying needle carried at one side of said work support, a loop-taker journaled in said sewing machine at the opposite side of said work support and having a needle loop seizing beak and a thread carrying bobbin associated therewith, and means for actuating said needle and loop-taker in timed relation as is required in the formation of lock stitches, a bobbin replenishing means including a means for clamping a needle thread loop on said loop seizing beak and a means for directing one limb of said clamped needle thread loop to said bobbin, operator influenced means for at will rendering said bobbin replenishing means effective, a nipping and cutting means for the free end of a thread carried by the needle, and means securing said nipping and cutting means on said sewing machine at that distance from said loop-taker as to provide from the thread clamping means on the loop seizing beak to the nipping and cutting means a length of free end of needle thread sufliciently short as to be drawn by said loop seizing beak and such thread clamping means completely to that side of the work support occupied by said loop-taker.

24. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means effective to replenish a supply of thread into said locking thread accommodating means of said loop-taker during said operation of said needle and loop-taker by said actuating means, operator influenced means for at will rendering said locking thread replenishing means effective, latch means for maintaining said thread replenishing means in effective position, a ratchet wheel journaled in said sewing machine, latch release means associated with said ratchet wheel, a ratchet wheel driving pawl, means 2th operated by said actuating mechanism during operation of said needle and loop-taker for oscillating said driving pawl, a driving pawl throw-out means, and means associated with said operator influenced means for rendering said driving pawl throwout means ineffective while said thread replenishing means is effective.

25. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means effective to replenish a supply of thread into said locking thread accommodating means of said loop-taker during said operation of said needle and loop-taker by said actuating means, operator influenced means for at will rendering said locking thread replenishing means effective, latch means for maintaining said thread replenishing means in effective position, a ratchet wheel journaled in said sewing machine, means on said ratchet wheel and on said sewing machine providing a positive stop limiting turning movement of said ratchet wheel in one direction, means biasing said ratchet wheel in one direction of rotation against said stop means, cam means carried by said ratchet wheel, latch release means carried by said sewing machine in the path of said cam means a ratchet wheel driving pawl, means operated by said actuating mechanism during operation of said needle and loop-taker for oscillating said driving pawl, a retrograde motion pawl, pawl throw-out means for shifting said pawls simultaneously into or out of operative engagement with said ratchet wheel, and means associated with said operator influenced means for moving said pawl throw-out means to shift said pawls into operative engagement with said ratchet wheel while said thread replenishing means is effective.

26. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for cooperating movement as is required for the formation of lock stitches, locking thread replenishing means effective to replenish a supply of thread into said locking thread accommodating means of said loop-taker during said operation of said needle and loop-taker by said actuating means, operator influenced means for at will rendering said locking thread replenishing means effective, latch means for maintaining said thread replenishing means in effective position, a rotatable counting member journaled on an axis fixed relatively in said sewing machine, cam means carried by said counting member, stop means on said counting member and said sewing machine limiting turning movement of said counting member, means for biasing said counting member in one direction of rotation against said stop means, drive means operated by said actuating means during operation of said needle and loop-taker for periodically imparting increments of turning movement to said rotatable counting member in opposition toward biasing means in timed relation with the stitch forming movements of said needle and looptaker, said latch means including a latch lever having one extremity disposed axially of said counting member, a shaft journaled coaxially of said counting member, a latch release lever fulcrumed relatively to said shaft, :1 first extremity of said latch release lever disposed in the path of said cam means as said counting member, a second extremity of said latch release member disposed axially of said counting member and in engagement with said latch lever, means for turning said shaft to position the first extremity of said latch release member at a selected angular distance from the position of the cam means in the stopped position of said counting member, means associated with said operator influenced means for operatively connecting said drive means with said counting member while said thread replenishing means is effective, and means associated with said latch release lever for separating said drive means from said counting member upon release of said latch lever.

27. In a lock stitch sewing machine having a frame including a flat work supporting cloth plate, a thread carrying needle carried in said frame at one side of said cloth plate, a loop-taker journaled in said frame at the opposite side of said cloth plate and having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and looptaker for repetitive cooperating movements as are required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to introduce a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, means for at will rendering said locking thread replenishing means eifective, latch means for maintaining said thread replenishing means in effective position, latch release means associated with said latch means, and means driven by said actuating means and responsive to a predetermined number of repetitive cooperating lock stitch forming movements of said needle and loop-taker for operating said latch release means, and operator influenced control means for selecting said predetermined number of repetitive cooperating lock stitch forming movements required for operating said latch release means, said control means including a shallow circular recess formed in said cloth plate, an operator influenced disk arranged in said recess and disposed substantially flush with said cloth plate, means journaling said disk in said sewing machine frame on an axis substantially perpendicular to said cloth plate and cooperating indicia carried on said operator influenced disk and on said cloth plate providing a visual indication of the angular position of adjustment of said disk.

28. A sewing machine as set forth in claim 26 having a frame including a fiat work supporting cloth plate, in which said counting member is journaled beneath said cloth plate on an axis substantially perpendicular to said cloth plate, an operator influenced disk disposed on and substantially flush with said cloth plate, means securing said disk to said shaft, and cooperating indicia on said disk and on said cloth plate providing a visual indication of the angular position of adjustment of said shaft.

29. A sewing machine as set forth in claim 28 including releasable locking means carried by said sewing machine frame and engageable with said disk for securing said disk in selected position of adjustment.

30. In a lock stitch sewing machine having a thread carrying needle, a loop-taker having means therein to accommodate a supply of locking thread, and actuating means operatively connecting said needle and loop-taker for repetitive cooperating movements as are required for the formation of lock stitches, locking thread replenishing means driven by said actuating means and effective to introduce a supply of thread into said locking thread accommodating means in said loop-taker during said operation of said needle and loop-taker by said actuating means, means for at will rendering said locking thread replenishing means effective, latch means for maintaining said thread replenishing means in effective position, latch release means associated with said latch means, and means driven by said actuating means and responsive to a predetermined number of said repetitive cooperating lock stitch forming movements of said needle and loop-taker for operating said latch release means, and operator influenced control means for selecting said predetermined number of repetitive cooperating lock stitch forming movements required for operating said latch release means, a signalling means carried by said sewing machine for providing a noticeable indication to the machine operator, and means associated with said latch release means and effective in less than said predetermined number of repetitive cooperating lock stitch forming movements of said needle and loop-taker for energizing said signalling means.

31. A sewing machine as set forth in claim 26 including an electrically operated signal lamp carried by said sewing machine, electrical switch means operatively connected to said signal lamp, a switch actuating lever carried by said shaft, a first extremity of said switch actuating lever disposed in the path of said cam means and on that side of said first extremity of said latch release lever toward which said cam means is driven, and a second extremity of said switch actuating lever operatively arranged to close said switch means upon engagement of said cam means with the first extremity of said switch actuating lever.

References Cited in the file of this patent UNITED STATES PATENTS 349,029 Bihl et al. Sept. 14, 1886 1,118,450 Siobald Nov. 24, 1914 1,794,255 Stephenson Feb. 24, 1931 1,906,087 Parker Apr. 25, 1933 2,098,327 Winkley Nov. 9, 1937 2,225,370 Day Dec. 17, 1940 2,438,636 Ivandick Mar. 30, 1948 FOREIGN PATENTS 1,224,744 France 1 Feb. 8, 1960 

1. IN A LOCK STITCH SEWING MACHINE HAVING A THREAD CARRYING NEEDLE, A LOOP-TAKER HAVING MEANS THEREIN TO ACCOMMODATE A SUPPLY OF LOCKING THREAD, AND ACTUATING MEANS OPERATIVELY CONNECTING SAID NEEDLE AND LOOP-TAKER FOR COOPERATING MOVEMENT IN TIMED RELATION AS IS REQUIRED FOR THE FORMATION OF LOCK STITCHES, LOCKING THREAD REPLENISHING MEANS DRIVEN BY SAID ACTUATING MEANS AND EFFECTIVE TO REPLENISH A SUPPLY OF THREAD INTO SAID LOCKING THREAD ACCOMMODATING MEANS IN SAID LOOP-TAKER DURING SAID OPERATION OF SAID NEEDLE AND LOOP-TAKER BY SAID ACTUATING MEANS, A FIRST OPERATOR INFLUENCED MEANS FOR CONTROLLING THE OPERATION OF SAID SEWING MACHINE ACTUATING MEANS, AND A SECOND OPERATOR INFLUENCED CONTROL MEANS OPERATIVELY CONNECTED TO SAID LOCKING THREAD REPLENISHING 